Method for the manufacture of elongate concrete building blocks

ABSTRACT

A slide-molding machine for molding preferably elongate concrete elements, wherein the mold bottom consists of a flat bed over which at least one container holding concrete mixture is adapted to travel and the mold sides consist of two forming surfaces, one being rolled out in synchrony with the speed of advancement of the container, and the opposite forming surface being formed by a wall moving together with said container and vibrating in the lateral direction to compact the concrete mixture dispensed in the space or mold proper formed by said two molding surfaces. The invention also relates to a method of manufacturing elongate objects of concrete while using the slide-molding technique, said method being performed by discharging concrete into the one or several continuously advancing containers down onto the flat bed forming the mold bottom and vibrating the concrete to form a layer having parallel longitudinal edges and a smooth upper surface, wherein said layer is being formed between the feeder band and the forming wall positioned laterally relatively thereto and advancing together with said container, and by compacting said concrete being discharged between said band and said shaping wall.

United States Patent [191 Nilsson 1 Sept. 16, 1975 [75] Inventor: Sven Melker Nilsson, Kallered,

Sweden [73] Assignee: Ingenjorsfirman Nilcon AB,

Kallered, Sweden [22] Filed: Feb. 26, 1973 [21] App]. No.: 335,485

52 user. 264/70; 264/7l;425/64 51 int. c1 ..B28bl/08 58 Field of Search ..264/33,34,70-72;

[56] References Cited UNITED STATES PATENTS 1 H1925 Nelson 249/20 X 2/1970 Barron 9/1971 Joncll et a1. 264/70 FOREIGN PATENTS OR APPLICATIONS 40,121 5/1956 Poland 425/63 Primary Examiner-Robert F. White Assistant Examiner-Thomas P. Pavelko Attorney, Agent, or Firm-Harness, Dickey & Pierce [5 7] ABSTRACT A slide-molding machine for molding preferably elongate concrete elements, wherein the mold bottom consists of a flatbed over which at least one container holding concrete mixture is adapted to travel and the mold sides consists of two forming surfaces, one being rolled out in synchrony with the speed of advancement of the container, and the opposite forming surface being formed by a wall moving together with said container and vibrating in the lateral direction to compact the concrete mixture dispensed in the space or mold proper formed by said two molding surfaces. The invention also relates to a method of manufacturing elongate objects of concrete while using the slidemolding technique, said method being performed by discharging concrete into the one or several continuously advancing containers down onto the flat bed forming the mold bottom and vibrating the concrete to form a layer having parallel longitudinal edges and a smooth upper surface, wherein said layer is being formed between the feeder band and the forming wall positioned laterally relatively thereto and advancing together with said container, and by compacting said concrete being discharged between said band and said shaping wall.

4 Claims, 12 Drawing Figures PATENTED SEP 1 6 I975 SHEET 1 BF 5 PATENTED SEP I 6 I975 SHEET 2 [IF 5 PATENTED SEP 1 8 I875 SHEET 3 BF 5 PATENTED SEP I 8 I975 sum 5 o 5 Fig.7]

METHOD FOR THE MANUFACTURE OF ELONGATE CONCRETE BUILDING BLOCKS This is a division of application Ser. No. 195,200, filed Nov. 3, 197], now US. Pat. No. 3,740,176.

BACKGROUND OF THE INVENTION It is already known to manufacture elongate and comparatively thin and edgewise arranged concrete building blocks by using the slide mould technique according to which a concrete mixture is being discharged from a continuously advancing container down onto a bed, vibrated directly beneath said container, and formed into a layer the longitudinal sides of which being parallel relatively each other and the upper surface of which smoothened. Because the two vibrating side walls of the mould during the continuous advancement thereof on the bed slide in a direction towards the concrete object thus formed, there is a risk that cracks may form as a result of the friction between the forming wall and the concrete object. For this reason, the advancing speed of the slide mould must be limited. As a rule, the speed cannot exceed 1.5-2 meters per minute.

BRIEF SUMMARY OF THE INVENTION The purpose of the present invention is primarily to attempt to increase the moulding speed proper and yet obtain a concrete element of predetermined dimensions exhibiting no cracks. In accordance with the in vention this is made possible in that the concrete layer is being moulded between a vertically positioned feeder band and a forming wall, said feeder band being rolled out in synchrony with the speed of advancement of the container and the forming wall being positioned at a distance laterally relatively said band and moving together with the container and being arranged to vibrate laterally in a manner known per se while compacting the concrete mixture fed into the space between said band and said wall from the container. Owing to the combination of a feeder band, rolled out as indicated, and a vibrating forming wall arranged at a distance from said band and extending in the advancing direction of the mould, it becomes possible to increase the moulding speed to 6 meters per minute or more. The manufacturing costs naturally are reduced accordingly. Because there is no relative displacement between the feeder band and the moulded concrete element there is no risk of crack formation in the element.

When forming elements between two vibrating forming walls running in parallel in accordance with earlier known methods an extremely accurate adjustment of the forming walls as well as careful metering of the concrete mixture from the container is required. By using a feeder band in combination with a vibrating forming wall in the mould it becomes possible to allow the gap between these two mould parts to taper in the direction towards the rear mould end and to apply a load to the rear end of the resilient wall while using a resilient means such that said wall may swing to the side to permit a momentary increase of the mould width at the mould outlet end when an excess of concrete mass is being discharged from the container. In such cases the concrete element is given a slightly increased thickness in the corresponding area but this does not, however, constitute a drawback. Nor is there in this area any risk that cracks may occur which of course is of importance.

The invention also concerns a machine for performing the novel method, said machine comprising a frame which is movable over an elongate bed in the longitudinal direction thereof and which is provided with one or several containers intended to hold the concrete mixture, said container or containers having concrete mix ture outlet openings at their lower portion, and forming side walls for moulding the side faces of the concrete layer being formed on the bed. The characterising feature of the invention is the provision of a vertically positioned feeder band constituting one of the forming sides and adapted to be rolled out at the same speed as theframe is being advanced on the bed, and of a vertically positioned wall constituting the opposite forming side and having means to vibrate it laterally.

In accordance with a preferred embodiment of the invention the feeder band is provided with recesses spaced equal distances apart. These recesses form corresponding projections on the external face of the moulded concrete element. When the latter is in the form of a supporting beam and two such supporting beams are placed adjacent one another and joined together by means of, for instance, mortar, these projections ensure a strong bond between the beams and prevent the latter from being displaced relatively each other in the horizontal or the vertical directions.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics of the invention and the advantages obtained thereby will become apparent upon reading the following detailed description, in which:

FIGS. 1-3 illustrate schematically a machine in accordance with the invention,

FIG. 1 being a side view showing in partial longitudinal section a machine for the manufacture of a channel-shaped beam of concrete,

FIG. 2 being a cross-sectional view through the ma chine along line II-II in FIG. I with certain parts broken away for the sake of clarity, and

FIG. 3 being a plan view of the left side of the machine opposite one feeder band thereof.

FIG. 4 illustrates in a side view a more detailed arrangement of the machine.

FIG. 5. illustrates on an enlarged scale a plan view of the machine in accordance with FIG. 4.

FIG. 6. is also a plan view of the machine in accordance with FIG. 5, the concrete mixture containers having, however, been omitted therefrom.

FIG. 7 is a cross sectional view through the machine and illustrates on an even larger scale a cross-section through the machine along line VII\ II of FIG. 6.

FIG. 8 is a cross sectional view along line VIIIVIII of FIG. 6.

FIG. 9 shows on an even larger scale a modified embodiment of the device for supporting the right vibrating forming wall in accordance with FIG. 8.

FIG. 10 is a perspective view of one end of a concrete element formed by the machine in accordance with the previous Figures.

FIG. 11 is a perspective view of armouring irons included in the concrete elements, and

FIG. 12 is a vertical section through two mutually interconnected concrete elements.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT .FIG. 10 illustrates a furrow-like or channel-shaped concrete element 1 having two vertical walls 2, 3 and a bottom 4 extending between said walls. The concrete element 1 is reinforced by means of U-shaped, longitudinally extending armouring irons 5 and transversally extending armouring irons 6 having upright end portions or legs 7. Additionally, a longitudinal armouring iron 8 is arranged inside each wall 2, 3. Each channel wall 2, 3 is provided on its external face with projections 9 spaced an equal distance apart. Concrete elements of this kind are intended to be manufactured by means of the machine in accordance with the invention while using the slide-moulding technique.

' The frame 10 of the moulding machine illustrated in FIGS. 49 is supported on running wheels 11, 12 running along the longitudinal edges 13 of an elongate bed 14. The wheels 12 are driven by a motor 15 via chains 16 or other motion-transmitting means. The frame 10 supports three moulds 17, 18, and 19 for moulding the channel walls 2, 3 and bottom 4, respectively, of the concrete-element 1. The bottom of each mould 17, 18, and 19 is formed by bed 14.

The outer wall of the moulds 17, 18 is formed by a vertically positioned feeder band 20, 21 made from rubber or some other suitable resilient material. Each band runs over two vertical rollers 22, 23 the latter of which is driven by the motor 15 at such a speed and in such a direction as to permit the bands 20, 21 to be rolled out at the rate of advancement of the machine along the bed. This means that the side of each band 20, 21 facing its associated mould 17, 18 does not move relatively the moulded object. A supporting wall 24 positioned in contact with the reverse side of the band 20, 21 takes up the pressure from the mould. The bands 20, 21 are provided with outwardly projecting, vertical ribs or similar projections 25 spaced an equal distance apart along the lower edge of the bands. The bands form the outer forming or moulding walls of the moulds 17, 18. The opposite forming wall of each mould 17 and 18 comprise an elongate plate 27 and 28, respectively, these plates being provided with vibrator means 26 and supported through resilient means 29, 30 and 31, 32, respectively, arranged at the forward and the rear ends, respectively, on horizontal shafts 33, which are rigidly connected to longitudinally extending beams 34 on the frame 10. Special means are provided to displace walls 27, 28 to positions closer to or further away from each band 20, 21 to lessen or increase, according to wish, the width of the moulds and consequently the thickness of the channel walls 2, 3.

As illustrated in FIG. 9 it is also possible to adjust the walls 27, 28 in such a way that each mould 17, 18 will taper in the direction towards the trailing end 35, i.e. such that the walls 27, 28 converge towards the bands 20, 21 in the rearward direction the advancing direction of the moulding machine being indicated by arrow 36 in FIG. 1. In accordance with FIG. 9 the shaft 33 is provided with external screw threads meshing with internal screw threads in a nut sleeve 37, which sleeve is rotatably, but axially not displacably mounted in its associated beam 34.

At its top portion, each mould 17, 18 terminates in a slide 39 connected to a vibrator means 38. The moulds 17, 18 also comprise longitudinally extending shaping ribs 40 and 41 positioned immediately above the bed 14.

The mould 19 intended for moulding the bottom 4 of the channel also terminates at its top portion in a slide 43 which is associated with a vibrator means 42 and has resilient and longitudinallyextending sealing ribs 44 which are loosely united with the forming walls 27, 28.

Ahead of the moulds l7, l8, and 19., as seen in the direction of advancement of the moulding machine, the frame 10 supports two containers 45, 46 holding a concrete mixer, each such container comprising a metering device 47 and 48, respectively, arranged at the outlet opening 49 and 50, respectively. Below the outlet opening 49 a funnel 51 or similar means is arranged to spread concrete mixture in an even layer 52 in the middle of the bed 14. Ahead of the funnel 51 a nozzle 53 is arranged, said nozzle being connected to a water supply for spraying water onto the slope 54 being formed at the forward edge of the concrete layer 52.

Below the outlet or discharge opening 50 a distributor funnel 55 is mounted to divide the concrete being discharged from the container 46 in such a way that an equal amount of concrete flows down into each mould 17 and 18. Immediately below each outlet openings 56 of the distributor funnel 55 is positioned the rear end of a guide pipe 57 for the longitudinal amouring iron 8. The pipe 57 is connected to a source of water supply such that the amouring iron 8 when leaving the rear end of the guide pipe 57, is wet and, in addition the slope 58 being formed at the forward end of the concrete layer 59 formed at the end walls 2 and 3, respectively, is somewhat wetted.

The machine operates in the following manner. Initially, the amouring irons 5, 6, and 7 which have been previously put in order and partly shown in FIG. 11 are placed centrally on the bed 14 in the longitudinal direction of said bed such that the uprights 7 of the armours extend into the moulds l7 and 18 of the machine. When the latter is put into motion and driven at a predetermined speed in the direction indicated by arrow 36 in FIG. 1, a concrete mixture is being dispensed out of the container 45 down onto the centre field of bed 14 in a layer 52 of sufficient thickness. The layer is being compacted by the vibrator means 42 and smoothened by the slide 43. At the same time, concrete is being discharged from container 46 down between the iron uprights 7 in the moulds 17, 18, where the concrete mixture is being compacted primarily through the vibrating of the walls 27, 28 and to some extend also through the vibrating of the slides 39, which latter means simultaneously smoothen the upper edge of the concrete element 1 just moulded. The slides 39 are so adjusted that the walls 2 and 3 are given the intended correct height. Also the forming walls 27, 28 are adjusted at the correct distance away from their associated band 20, 21. It is then possible to allow the forming walls 27, 28 and the bands 20, 21 to converge towards the outlet end (rear end) of the moulds 17, 18 by approximately 20, which facilitates the feeding of the concrete and also makes possible to compact it heavily in the moulds 17, 18. If, for some reason, a momentary excess of concrete mixture 15 discharged from the container 46 into the moulds, the walls 27, 28 bulge to a corresponding degree at their rear end 35 away from its associated band 20, 21. The result then is that the walls 2, 3 will become somewhat thicker in this area, which obviously has no detrimental effect on the concrete element itself. The transverse dimensions ofwalls 24 which are non-resilient in an outwards direction. This arrangement ensures that the finished concrete elements all are given the same width and the channel walls 2 and 3 also the same-height.

To make possible that the concrete mixture streams continuously and in an even flow down onto the bed 14 a relatively dry concrete mixture is used. The water cement ratio should as a rule be as low as about 0.27-0.35. As a consequence of this comparatively low water/cement ratio a product of great strength and tenacity is obtained. Another advantage inherent with this concrete mixture is that sticking between the side surfaces of the formed product and the sides of the mould is eliminated. However, in order to ensure that during compacting the dry concrete mixture is made to completely enclose the annouring irons 5, 6, a small amount of water is added through nozzle 53 to the concrete layer 52, and to ensure that the longitudinal armouring irons 8 are likewise well embedded in the concrete a small amount of water is added through pipe 57 such that the concrete mixture around the iron 8 becomes more fluid and easy-flowing.

FIG. 12 illustrates the way in which two concrete elements 1 manufactured in accordance with the invention and resting on a transverse beam 60 are interconnected with mortar inserted in the gap 61 between the adjacent longitudinal walls 2, 3 of the elements. Because the mortar penetrates between the projections 9 on the elements a firm bond is obtained, rendering impossible mutual displacement of the concrete elements relatively each other in the vertical as well as in the longitudinal direction.

The embodiment as shown and illustrated is to be re garded as an example only and the various parts of the moulding machine may be varied constructively in a variety of ways within the scope of the appended claims. For instance, the invention is not limited to moulding channel-chaped concrete elements but also other, relatively narrow beams, such as T-beams, positioned on their small edge, are with the same advantage and with the same manufacturing capacity manufactured by means of a machine in accordance with the present invention.

What I claim is:

1. A method of manufacturing through slidemoulding concrete building elements of elongate configuration, said method comprising the stage of discharging a concrete mixture vertically from a continuously advancing container onto a horizontally ending bed, vibrating the upper surface of said concrete to form a layer having mutually parallel longitudinal edges and a smooth upper surface, moulding said layer between two walls at least one of which consisting of a vertically positioned feeder band, rolling said feeder band in synchronism with the speed of advancement of the container, and vibrating at least one of said forming walls in the lateral direction compacting the concrete mixture being discharged into the space formed between said band and said forming walls from said container.

2. The method as set forth in claim 1 wherein the vibrating forming wall comprises a second wall spaced from the feeder band.

3. The method as set forth in claim 1 further compris ing the step of compacting the concrete mixture in the space between the walls by decreasing the cross sectional area of the space as the container moves relative to the discharged concrete.

4. The method as set forth in claim 3 wherein the vibrating forming wall comprises a second wall spaced from the feeder band. 

1. A METHOD OF MANUFACTURING THROUGH SLIDE-MOULDING CONCRETE BUILDING ELEMENTS OF ELONGATE CONFIGURATION, SAID METHOD COMPRISING THE STAGE OF DISCHARGING A CONCRETE MIXTURE VERTICALLY FROM A CONTINUOUSLY ADVANCING CONTAINER ONTO A HORIZONTALLY ENDING BED, VIBRATING THE UPPER SURFACE OF SAID CONCRETE TO FORM A LAYER HAVING MUTUALLY PARALLEL LONGITUDINAL EDGES AND A SMOOTH UPPER SURFACE, MOULDING SAID LAYER BETWEEN TWO WALLS AT LEAST ONE OF WHICH CONSISTING OF A VERTICALLYY POSITIONED FEEDER BAND, ROLLING SAID FEEDER BAND IN SYNCHRONISM WITH THE SPEED OF ADVANCEMENT OF THE CONTAINER, AND VIBRATING AT LEAST ONE OF SAID FORMING WALLS IN THE LATERAL DIRECTION COMPACTING THE CONCRETE MIXTURE BEING DISCHARGED INTO THE SPACE FORMED BETWEEN SAID BAND AND SAID FORMING WALLS FROM SAID CONTAINER.
 2. The method as set forth in claim 1 wherein the vibrating forming wall comprises a second wall spaced from the feeder band.
 3. The method as set forth in claim 1 further comprising the step of compacting the concrete mixture in the space between the walls by decreasing the cross sectional area of the space as the container moves relative to the discharged concrete.
 4. The method as set forth in claim 3 wherein the vibrating forming wall comprises a second wall spaced from the feeder band. 